Temporal pulse shaping for laser shock peening

Abstract

Methods, systems, and apparatuses are disclosed for temporal pulse shaping of laser pulses used in laser shock peening applications. In one embodiment, a system for temporal pulse shaping of a laser beam used for laser shock peening comprises a laser; a modulator; a high voltage driver, a waveform generator, a polarizer, and an optical amplifier.

The invention claimed is: 
     
       1. A method for temporal pulse shaping of a laser beam used for laser shock processing of a workpiece, comprising:
 (1) determining at least one of a magnitude and depth of residual stress desired at one or more locations on the workpiece and selecting a pulse width and a temporal profile of the laser beam corresponding to the at least one of a magnitude of residual stress and depth of residual stress; 
 (2) inputting the laser beam into a modulator; 
 (3) generating a waveform from a waveform generator based on the selected pulse width and the selected temporal profile; 
 (4) inputting the generated waveform into a high voltage driver to output a high voltage signal; 
 (5) inputting the high voltage signal into the modulator to modulate and shape a temporal profile of the laser beam based on the selected pulse width and the selected temporal profile; 
 (6) amplifying the modulated and shaped laser beam; and 
 (7) delivering the amplified, modulated, and shaped laser beam to the one or more locations on the workpiece. 
 
     
     
       2. The method of  claim 1 , further comprising generating the laser beam with a laser comprising at least one of a continuous wave (CW) laser, a CW fiber laser, a diode pumped (CW) laser; a diode pumped CW fiber laser; and a long pulse laser oscillator. 
     
     
       3. The method of  claim 1 , wherein the laser beam is input into a modulator comprising at least one of an electro-optic modulator; an acousto-optic modulator; and an electro-optic Pockels cell. 
     
     
       4. The method of  claim 1 , wherein the pulse width of the laser beam is between 5 ns and 40 ns. 
     
     
       5. The method of  claim 1 , further comprising operating a processing device to execute instructions to output a time dependent voltage signal from the waveform generator and input the time dependent voltage signal to the high voltage driver, and wherein a time dependent high voltage signal output from the high voltage driver shapes a temporal profile of the laser beam.